change bmp info to use common header parser

stb_image.h

@@ -6088,29 +6088,17 @@ static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp)
 #ifndef STBI_NO_BMP
 static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp)
 {
-   int hsz;
-   if (stbi__get8(s) != 'B' || stbi__get8(s) != 'M') {
-       stbi__rewind( s );
-       return 0;
-   }
-   stbi__skip(s,12);
-   hsz = stbi__get32le(s);
-   if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) {
-       stbi__rewind( s );
-       return 0;
-   }
-   if (hsz == 12) {
-      *x = stbi__get16le(s);
-      *y = stbi__get16le(s);
-   } else {
-      *x = stbi__get32le(s);
-      *y = stbi__get32le(s);
-   }
-   if (stbi__get16le(s) != 1) {
-       stbi__rewind( s );
-       return 0;
-   }
-   *comp = stbi__get16le(s) / 8;
+   void *p;
+   stbi__bmp_data info;
+
+   info.all_a = 255;   
+   p = stbi__bmp_parse_header(s, &info);
+   stbi__rewind( s );
+   if (p == NULL)
+      return 0;
+   *x = s->img_x;
+   *y = s->img_y;
+   *comp = info.ma ? 4 : 3;
    return 1;
 }
 #endif

tests/image_test.c

@@ -81,15 +81,17 @@ int main(int argc, char **argv)
 
       for (i=1; i < argc; ++i) {
          int res;
+         int w2,h2,n2;
          unsigned char *data;
          printf("%s\n", argv[i]);
-         res = stbi_info(argv[1], &w, &h, &n);
+         res = stbi_info(argv[1], &w2, &h2, &n2);
          data = stbi_load(argv[i], &w, &h, &n, 4); if (data) free(data); else printf("Failed &n\n");
          data = stbi_load(argv[i], &w, &h,  0, 1); if (data) free(data); else printf("Failed 1\n");
          data = stbi_load(argv[i], &w, &h,  0, 2); if (data) free(data); else printf("Failed 2\n");
          data = stbi_load(argv[i], &w, &h,  0, 3); if (data) free(data); else printf("Failed 3\n");
-         data = stbi_load(argv[i], &w, &h,  0, 4);
+         data = stbi_load(argv[i], &w, &h, &n, 4);
          assert(data);
+         assert(w == w2 && h == h2 && n == n2);
          assert(res);
          if (data) {
             char fname[512];